1 files changed, 36 insertions, 8 deletions
diff --git a/android/text/style/SubscriptSpan.java b/android/text/style/SubscriptSpan.java
index f1b0d38c..3d15aad6 100644
--- a/android/text/style/SubscriptSpan.java
+++ b/android/text/style/SubscriptSpan.java
@@ -16,46 +16,74 @@
 
 package android.text.style;
 
+import android.annotation.NonNull;
 import android.os.Parcel;
 import android.text.ParcelableSpan;
 import android.text.TextPaint;
 import android.text.TextUtils;
 
+/**
+ * The span that moves the position of the text baseline lower.
+ * <p>
+ * The span can be used like this:
+ * <pre>{@code
+ *  SpannableString string = new SpannableString("☕- C8H10N4O2\n");
+ *string.setSpan(new SubscriptSpan(), 4, 5, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
+ *string.setSpan(new SubscriptSpan(), 6, 8, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
+ *string.setSpan(new SubscriptSpan(), 9, 10, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
+ *string.setSpan(new SubscriptSpan(), 11, 12, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);}</pre>
+ * <img src="{@docRoot}reference/android/images/text/style/subscriptspan.png" />
+ * <figcaption>Text with <code>SubscriptSpan</code>.</figcaption>
+ * Note: Since the span affects the position of the text, if the text is on the last line of a
+ * TextView, it may appear cut.
+ */
 public class SubscriptSpan extends MetricAffectingSpan implements ParcelableSpan {
+
+    /**
+     * Creates a {@link SubscriptSpan}.
+     */
     public SubscriptSpan() {
     }
-    
-    public SubscriptSpan(Parcel src) {
+
+    /**
+     * Creates a {@link SubscriptSpan} from a parcel.
+     */
+    public SubscriptSpan(@NonNull Parcel src) {
     }
-    
+
+    @Override
     public int getSpanTypeId() {
         return getSpanTypeIdInternal();
     }
 
     /** @hide */
+    @Override
     public int getSpanTypeIdInternal() {
         return TextUtils.SUBSCRIPT_SPAN;
     }
-    
+
+    @Override
     public int describeContents() {
         return 0;
     }
 
+    @Override
     public void writeToParcel(Parcel dest, int flags) {
         writeToParcelInternal(dest, flags);
     }
 
     /** @hide */
+    @Override
     public void writeToParcelInternal(Parcel dest, int flags) {
     }
 
     @Override
-    public void updateDrawState(TextPaint tp) {
-        tp.baselineShift -= (int) (tp.ascent() / 2);
+    public void updateDrawState(@NonNull TextPaint textPaint) {
+        textPaint.baselineShift -= (int) (textPaint.ascent() / 2);
     }
 
     @Override
-    public void updateMeasureState(TextPaint tp) {
-        tp.baselineShift -= (int) (tp.ascent() / 2);
+    public void updateMeasureState(@NonNull TextPaint textPaint) {
+        textPaint.baselineShift -= (int) (textPaint.ascent() / 2);
     }
 }